The two aims of the Immnoassay Core are 1) to perform the antigen specific antibody assays, and 2) to candidate the lymphokines and/or cytokines produced by lymphocytes and antigen presenting cells cultured in presence of antigen. Performing this assay in a core laboratory assures that the antibodies and cytokines are measured in a standardized and uniform manner for the different experiments performed by investigators of three subprojects. Specific functions of the first aim are to routinely quantitate the specific IgG2a, IgG1 and EgE antibodies in all mice that were immunized under different conditions. In addition, assays will be made available to quantitate specific antibodies of the other isotypes and quantitation of total IgE levels, assays that will be needed for special experiments and for control purposes in the study of the nature of pDNA immunization. These measurements will be performed by enzyme linked and radioimmunoassays (ELISA and RIA) that have been established in our laboratories during our previous work on the regulation of IgE antibody formation. The specific function of the second aim of the is core is to determine the interferon-gamma (IFN-gamma) and interleukin 4 (Il-4) production in cell supernatants. In addition assays will be performed for quantitation of other lymphokines and cytokines, especially IL-2, IL-5, and interferon-beta (IFN-beta). In order to avoid dominance or special preference of the core facility for one or the other project, first priority independent of the project will be given to IgE analyses since control of IgE formation is the primary objective of the grant and knowledge of the effect of different experimental conditions on IgE formation is crucial for planning subsequent experiments.